Tobacco smoking remains one of the most significant preventable causes of death in the U.S. Although most smokers are interested in quitting, only one in five are ready to make a quit attempt at any point in time. Unfortunately, few interventions designed to enhance motivation or readiness among smokers who are not ready to quit are available. One intervention method that focuses on enhancing motivation for and commitment to behavior change is Motivational Interviewing (MI). MI has been shown to be effective for addressing a variety of addictive and health behaviors, however findings for smoking cessation have been overwhelmingly negative and all prior studies have significant limitations. One important limitation of prior studies is that they were not designed to directly test whether MI is more effective for smokers who are not ready to quit, and in particular, whether MI was more effective at motivating quit attempts. Moreover, nearly all focused on special populations such as public housing residents, adolescents, and people with mental illness, many of whom face significant environmental and physiological barriers to quitting. Therefore, the primary aim of this study is to test, among a sample of general adult smokers, the effectiveness of MI for motivating quit attempts among smokers not yet ready to quit. We will randomly assign eligible smokers to Motivational Interviewing (MI), a PHS Guidelines-based counseling control (GBC), or brief advice (BA). The primary outcome will be the occurrence (or not) of any self-reported quit attempt lasting at least 24 hours between randomization and 6 month follow-up. The secondary aim will be to examine 6 month follow-up quit rates between the groups in order to provide an effect size estimate that could be used in designing a large scale study with a primary outcome of smoking cessation. Participants in BA will receive 1 session and participants MI and GBC will receive 5 individual sessions (2 in-person, 3 phone) over 7 weeks. All participants who decide to quit will be provided with varenicline (Chantix). We project needing to enroll 255 smokers who are not ready to quit to detect the proposed treatment effect. PUBLIC HEALTH RELEVANCE: Tobacco smoking remains one of the most significant preventable causes of death in the U.S. and although most smokers are interested in quitting, four in five are not ready to make a quit attempt at any given point in time. This project addresses the lack of methods designed to increase readiness to quit by testing a novel counseling method known as Motivational Interviewing. The potential public health impact is large because it could extend the reach of effective cessation interventions to the majority of smokers who are unmotivated and reduce the decades-long lag between smoking initiation and cessation.